SGI: Hardware

Hi I am new to this board and SGi in general. I have an indigo 2 not powering on (no led, fan movement or anything) and am curious as to whether the power supply for an indigo 2 with impact graphics is proprietary like most other SGi stuff or if there are generic PSUs out there that will work with this system. I have read Ian Mapleson's reconditioning failed PSU article but I am not interested in messing with capacitors just replacing the PSU. Any opinions are appreciated.

I'm afraid the PSU is proprietary. What I'd try for starters though is to open it up and remove any none-essential components to see if it can power up. A failure of various components can place a short across the PSU and prevent it from turning on, so remove the HDDs, graphics card and RAM, then try it again for starters.

sunbeam477 wrote: Hi I am new to this board and SGi in general. I have an indigo 2 not powering on (no led, fan movement or anything) and am curious as to whether the power supply for an indigo 2 with impact graphics is proprietary like most other SGi stuff or if there are generic PSUs out there that will work with this system. I have read Ian Mapleson's reconditioning failed PSU article but I am not interested in messing with capacitors just replacing the PSU. Any opinions are appreciated.

Just take the psu out and test it with a good old multi meter. That'd be a good place to start.

Only word of caution I'd give is that a lot of earlier switch mode power supplies need a load of some sort to be placed across them, even if it's not a big one. Don't know for sure if this applies to the Indigo 2's PSU, but it's worth bearing in mind if you try to read voltage levels from it whilst powered up with nothing connected.

I once had a Indigo2 that was very sensitive to grounding issues, it would work on some outlets and not others in my old house with bad wiring - probably an easy thing to check

indyman007 wrote: Just take the psu out and test it with a good old multi meter. That'd be a good place to start.

Did you ever take one of these apart? There's a lot of cable inside which gets in the way of everything. Components are tightly packed -- changing those 4 capacitors can be a challenge already, never mind doing measurements inside a live specimen, where every mistake will easily turn the damn thing into an arc welder.

I wouldn't know how to start it unless if it's installed in an Indigo2 (there's no switch on it). But it will only install in an Indigo2 if it's closed, of course.

I've replaced capacitors in a couple of these and had roughly 50/50 success rate. If it worked: fine. If it didn't: trash. Oh, and I may be mistaken, but I have the feeling the pre-IMPACT PSUs don't suffer from this problem.

FWIW: the big difference between a ATX PSU and these things (other than the form factor) is that the PSU of an Indigo2 supplies lots of current on 3V3 and 5V rails. Modern PC power supplies don't do that: most current is supplied on the 12V rail(s) and regulators on the mainboard or graphics card convert it locally to whatever they need.

I have not! Making your point very fair and my suggestion rather useless, my mistake.